1、expat库简介
refer to wiki:
To use the Expat library, programs first register handler functions with Expat. When Expat parses an XML document, it calls the registered handlers as it finds relevant tokens in the input stream. These tokens and their associated
handler calls are called events. Typically, programs register handler functions for XML element start or stop events and character events. Expat provides for more sophisticated event handling such as XML Namespace declarations, processing instructions and
DTD events.
Expat is parsing events resemble the events defined in the Simple API for XML (SAX), but Expat is not a SAX-compliant parser. Projects incorporating the Expat library often build SAX and possibly DOM parsers on top of Expat. While Expat is mainly a stream-based
(push) parser, it supports stopping and restarting parsing at arbitrary times, thus making the implementation of a pull parser relatively easy as well.
为了使用Expat库，程序首先在Expart中住一个处理器函数（handler functions） 。当Expat解析XML文档时，发现输入流中有相关的令牌会调用已经注册的处理器(handlers) ，这些令牌(tokens)和其先关的处理器(handler)被称作事件。通常情况下， 程序会为XML元素中的开始事件、停止事件、字符事件（character events）注册处理函数。Expat提供了 更多复杂事件处理，例如XML命名空间声明，处理指令和DTD事件。
(第一次翻译，翻译的不好啊~~~)
说白了 ，Expat是一个面向流的xml解析器。
2、expat库的交叉编译
expat-2.0.1.tar.gz
./configure --host=arm-none-linux-gnueabi --prefix=/root/Qt/output/qt-arm/
make && make install
